JP6635559B2 - Vibration TIG welding method for work corners - Google Patents

Description

The present invention relates to a corner portion of a work formed by abutting ends of metal plates such as a stainless plate, a copper plate, and an aluminum plate at right angles, that is, a corner portion of a metal plate-bent work or a metal plate. A corner portion of a cylindrically bent work or a corner portion of a work in which two metal plates are butted to each other at right angles are joined and welded with a TIG welding torch having a constriction nozzle, In particular, a TIG welding torch equipped with a constriction nozzle is run in the welding direction while vibrating a corner of a workpiece formed of a metal plate having a thickness of 0.6 mm to 1.6 mm in a direction orthogonal to the corner of the workpiece. those related to the vibration TIG welding how the corner portion of the workpiece that is to be welded by.

  2. Description of the Related Art Conventionally, an automatic welding machine for corner-welding a corner portion of a work formed by bending a metal plate such as a stainless steel plate from the outside has been developed and put to practical use (for example, see Patent Document 1).

  In conventional corner welding of a work piece, a TIG welding torch is clamped according to a butt shape of a pair of left and right metal plates forming a corner part of a work piece after clamping a corner part of the work piece on a corner jig in an upward position. The welding is performed by swinging the tip of the tungsten electrode of the torch for TIG welding right or left above the abutting position of the corner of the workpiece W.

  That is, in the conventional corner welding of the work, as shown in FIG. 26A, of the pair of left and right metal plates W1 and W2 forming the corner portion of the work W, the tip surface W1a of the left metal plate W1 is formed. When welding a corner portion of a work W in which the outer surface W1b of the left metal plate W1 and the distal end surface W2a of the right metal plate W2 are flush with the inner surface W2c of the right metal plate W2. The TIG welding torch 101 is positioned above the ridgeline of the corner portion of the workpiece W such that the tip of the tungsten electrode rod 101a of the TIG welding torch 101 is located above the outer edge W1d of the tip surface W1a of the left metal plate W1. From the position (in this case, the outer edge W2d of the front end face W2a of the metal plate W2 on the right becomes a ridge line), the TIG welding torch 101 is moved to the corner of the workpiece W in this state. It is to be welded to the corner portion while moving me.

  Further, as shown in FIG. 26B, of the pair of left and right metal plates W1 and W2 forming the corner portion of the work W, the front end surface W2a of the right metal plate W2 is changed to the inner side surface W1c of the left metal plate W1. When welding the corner of the work W in which the outer surface W2b of the right metal plate W2 and the front end surface W1a of the left metal plate W1 are flush with each other, the tungsten of the torch 101 for TIG welding is used. The TIG welding torch 101 is positioned above the ridge line at the corner of the work W (in this case, the left metal plate) so that the tip of the electrode rod 101a is located above the outer edge W2d of the tip surface W2a of the right metal plate W2. The outer edge W1d of the tip end surface W1a of W1 is moved to the right from the ridgeline), and in this state, the TIG welding torch 101 is moved along the corner of the workpiece W to weld the corner. It is way.

  By the way, when the TIG welding torch 101 is welded to the corner portion of the work W while swinging the TIG welding torch 101 right or left from the position above the ridge line W1d, W2d of the corner portion of the work W, the shielding gas G is ridge line W1d of the corner portion of the work W , W2d flows to the left or right side, thereby causing the arc to flow to the left or right, becoming unstable, and losing the directivity of the arc (see FIGS. 25A and 25B). Therefore, the operator controlled the arc by manual welding.

  However, if the operator cannot control the arc and the arc flows to the left or right from the ridgelines W1d and W2d of the corners of the work W, the weld bead is formed at a position offset from the center position of the corner and the work is formed. In some cases, only one side of the corner portion of the W is melted to form a hole, and there is a problem that the quality of the welded work W is remarkably reduced.

  Further, since the TIG welding torch 101 melts a portion shifted left and right from the ridge lines W1d and W2d at the corners of the work W, the ridge lines W1d and W2d at the corners of the work W remain after welding is completed. The corner does not become a beautiful arc (see FIGS. 27A and 27B). Therefore, it is necessary to finish the corner portion of the work W with a sander or a belt sander after the welding is completed, and finally to finish the buffing, which requires a great deal of labor and time, and has a problem of noise and the like.

  Further, the TIG welding torch 101 is swung right or left according to the butting form of the pair of left and right metal plates W1 and W2 forming the corner of the work W. If it changes, the setting position of the TIG welding torch 101 must be changed each time, and if an operator sets the TIG welding torch 101 by mistake, poor welding (perforation or poor fusion) may occur. Become.

Utility Model Registration No. 2546453

The present invention has been made in view of such a problem, and an object of the present invention is to perform corner welding that has an excellent appearance shape of a welded portion and has no welding defects such as holes and the like. is to provide a vibration TIG welding how the corner portion of the workpiece that does not require finishing, such as sanding and buffing after completion.

  In order to achieve the above object, according to the method for vibration TIG welding of a corner portion of a work according to claim 1 of the present invention, a corner portion of a work formed by butting ends of a metal plate at right angles to a ridgeline thereof. After clamping in an upward facing position, a TIG welding torch with a constriction nozzle inside the outer nozzle is used to flow the shield gas to the outside and the inside and to eject the inner shield gas at a higher speed than the outer shield gas. A method of welding a corner portion of a work, wherein the work is run along a corner portion of the work while being vibrated in a direction orthogonal to a ridge line of the corner portion of the work to weld the corner portion of the work. Of the pair of left and right metal plates forming the corner portion, the tip surface of one side of the metal plate is attached to the inner side of the opposite side of the metal plate, and the tip of the side opposite to the outer side of the one side of the metal plate. After clamping the corner portion of the work formed by butting so that the surfaces are flush with each other, with the ridge line facing upward, the TIG welding torch is placed at a position where the amplitude of the torch is at least above the ridge line of the corner portion of the work. From the TIG welding torch and the corner of the workpiece while vibrating in the direction perpendicular to the ridge line of the corner of the workpiece so that the distance from the outer edge of the tip surface of the metal plate on one side to the position above the edge. Forming a molten pool at the corner of the work by the arc, and moving the molten pool in the same direction as the torch for TIG welding by moving the TIG welding torch along the corner of the work. Is characterized by welding.

  According to a second aspect of the present invention, there is provided the vibration TIG welding method for a corner portion of a workpiece according to the first aspect, wherein the torch for TIG welding provided with the constriction nozzle is vibrated. It is characterized in that the vibration is performed within the range of 1 Hz to 10 Hz.

  The method for vibrating TIG welding of a corner portion of a work according to the present invention uses a TIG welding torch provided with a constriction nozzle for improving the directivity of an arc, and places the TIG welding torch around a ridgeline position of a corner portion of the work. A molten pool is formed at the corner of the work while vibrating in the direction orthogonal to the corner, and the molten pool is moved in the same direction as the TIG welding torch by running the torch for TIG welding, thereby turning the corner of the work. Because the welding is performed, both sides of the ridge line at the corner of the work are melted evenly, and the molten metal at the corner of the work is rounded due to surface tension, and the corner of the work is formed into a beautiful circular arc and left and right It becomes a uniform shape.

As a result, the method of vibration TIG welding of the corner portion of the work according to the present invention is such that when the corner portion of the work is welded, a weld bead is formed at the center position of the corner portion of the work and welding defects such as holes are formed. , And the quality of the product produced by welding is remarkably improved.
Also, since the corner portion of the work is formed into a beautiful arc shape by the corner welding, finishing work such as sander finishing or buffing is not required after welding the corner portion of the work, so that much labor and time are not required. At the same time, the problem of noise can be eliminated.
Furthermore, since the TIG welding torch is vibrated, the temperature of the molten pool is made uniform and the metal structure can be prevented from becoming coarse.

It is a front view of the vibration TIG welding device of the corner of the work used for the method of the present invention. It is a side view of the vibration TIG welding apparatus of the corner part of a work similarly. It is a top view of the vibration TIG welding apparatus of the corner part of a work similarly. It is a perspective view of a lower jig unit and a clamp unit. It is a front view of a lower jig unit and a clamp unit. It is a side view of a lower jig unit and a clamp unit. It is a top view of a lower jig unit and a clamp unit. FIG. 4 is a front view showing a lower jig unit and a clamp unit, in a state where a corner portion of a box-bent work is sandwiched. It is a perspective view of a lower jig unit. It is a partially cutaway front view of a lower jig unit. It is a partially cutaway plan view of a lower jig unit. It is a partially cutaway front view of a clamp unit. FIG. 13 is a sectional view taken along line AA of FIG. 12. It is a perspective view of a torch unit. It is a front view of a torch unit. It is a side view of a torch unit. It is a top view of a torch unit. It is the perspective view which omitted some members of the torch unit. It is the partially notched top view which omitted some members of the torch unit. It is a longitudinal section of the torch for TIG welding provided with a constriction nozzle. It is a perspective view of a press holding member. It is a side view of the principal part of a jig unit and a clamp unit. It is explanatory drawing which shows the state which welds the corner part of a workpiece | work by the torch for TIG welding provided with a constriction nozzle. It is an expanded sectional view of the corner part of the work welded by the method and device of the present invention. 4 is a photograph showing the appearance of a corner portion of a workpiece welded by the method of the present invention and a conventional method. The state which welds the corner part of a workpiece with the conventional TIG welding torch is shown, (A) is an explanatory view of the state where the torch for TIG is swung to the left, and (B) is the state where the torch for TIG welding is swung to the right. FIG. It is an expanded sectional view of a corner part of a work welded by a conventional method.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
FIGS. 1 to 3 show a vibration TIG welding device for a corner portion of a work W used in the method of the present invention. The vibration TIG welding device is a metal plate such as a stainless plate, a copper plate, and an aluminum plate (for example, a plate having a thickness of 0 mm). (A metal plate of 1.6 mm to 1.6 mm) are abutted with each other at right angles, that is, a corner portion of the work W, that is, a corner portion of the work W in which the metal plate is box-bent or the metal plate is formed into a square cylindrical shape. The corner portion of the bent work W or the corner portion of the work W where two metal plates are butted to each other at right angles are jointed and welded by a TIG welding torch 53 having a constriction nozzle 53c that improves arc directivity. It is intended to be.

  As shown in FIGS. 1 to 3, the vibration TIG welding apparatus for the corner portion of the work W is composed of a frame 1 and a work W (hereinafter, the work W is bent in a box shape so that no gap is formed at the four corners. The lower jig unit 2 has a corner jig 18 for supporting the corner portion from the back side, and the upper surface of the corner jig 18 by pressing the corner portion of the work W supported by the corner jig 18 from above. And a constriction nozzle 53c that reciprocates along a corner portion of the work W and improves the directivity of an arc for joining and welding the corner portion of the work W. The torch unit 4 supporting the TIG welding torch 53 and the bottom surface near the corner of the work W supported by the corner jig 18 are connected to the front end surface 18 of the corner jig 18. And a pressing retaining member 5 to press and hold the.

  As shown in FIGS. 1 to 3, the frame 1 includes a base frame 1a in a horizontal posture and a box-shaped main body frame 1b provided on the base frame 1a. A power supply 6, a switchboard (not shown), a compressor (not shown) and the like are housed respectively.

  1 to 3, 7 is a touch-type operation panel, 8 is an automatic operation switch, 9 is a foot switch, 10 is a connection port for welding gas, etc., 11 is a safety cover, 12 is a caster, and 13 is a suspension. Eyebolt for

  As shown in FIGS. 4 to 11, the lower jig unit 2 includes a mandrel mounting base 14 in a vertical position, a substantially rectangular parallelepiped mandrel 15 fixed to a front surface of the mandrel mounting base 14, and a mandrel 15. A thick plate-shaped jig slide body 17 supported on the upper surface of the mandrel 15 via a linear guide 16 (comprising a guide rail 16a and a slider 16b sliding on the guide rail 16a) so as to be able to reciprocate in the longitudinal direction of the mandrel 15. The jig slide body 17 is detachably provided at the tip of the jig slide body 17, supports the corner of the work W from the back side, and absorbs excess heat when welding the corner of the work W to melt the bead. A corner jig 18 for preventing dropping, perforation, thermal distortion, and the like, and a mandrel 15 and a jig slide 17 are interposed between the corner jig 18 and the jig slide 17 and the mandrel 15. And a jig slide body drive unit 19 for reciprocating the jig slide body. The corner jig 18 is located below the right and left clamps 34 by the reciprocation of the jig slide body 17 (see FIG. 6). It is reciprocally movable in the front-rear direction over a position (dashed line position) and a front position (solid line position in FIG. 6) located diagonally downward and forward of the left and right clamps 34.

  Specifically, as shown in FIG. 9, the upper surface 18 a of the corner jig 18 is formed in a mountain shape by a copper member, and a concave groove 18 b formed on the lower surface of the corner jig 18 is fixed to the jig slide body 17. The jig is supported by the jig slide body 17 by fitting into a protruding ridge 17a formed on the upper surface on the tip end side. At this time, the corner jig 18 is supported by the jig slide 17 in a state where the corner jig 18 is positioned by the jig stopper 20 detachably attached to the protruding ridge 17 a of the jig slide 17.

  In this embodiment, the angle formed between one surface 18a of the mountain-shaped upper surface 18a of the corner jig 18 and the other surface 18a is set to 90 degrees, and the box is bent in a square or rectangular shape. The corner portion of the work W can be supported.

  As shown in FIGS. 6 and 10, the corner jig 18 includes a jig holding plate 22 provided on a side surface of the distal end portion of the jig slide 17 via a positioning pin 21, and a jig holding plate 22 and a jig. The clamp jig slide 17 is detachably attached to the jig slide 17 by a clamp lever 23 inserted into the slide jig 17, and when the clamp lever 23 is rotated in a tightening direction, the jig holding plate 22 turns the corner jig 18. Side and the jig slide body 17 side, and the corner jig 18 can be pressed and fixed to the jig slide body 17 side at the tip end (upper end) of the jig holding plate 22, and the clamp lever 23 can be moved. When the operation of turning in the loosening direction is performed, the jig holding plate 22 is in a free state, and the corner jig 18 can be removed from the jig slide 17.

  Further, as shown in FIGS. 6, 9 and 11, a hemmed portion (not shown) applied to the outer peripheral edge of the box-bent work W on the opening side is provided on the mountain-shaped upper surface 18a of the corner jig 18. Alternatively, a receiving groove 18c into which an inward flange portion (not shown) formed on the outer peripheral edge of the opening side of the box-bent workpiece W is formed. The position at which the receiving groove 18c is formed and the width of the groove 18c are set such that when the hemmed portion of the work W or the flange portion of the work W is inserted into the groove 18c, the inner surface of the bottom surface of the work W is moved to the front end surface of the corner jig 18. Each is set so that it can be brought into contact with 18f.

  As described above, the hemmed portion of the work W or the flange portion of the work W is inserted into the receiving groove 18c formed on the upper surface 18a of the corner jig 18 so that the corner portion of the work W is piled up from the back surface of the corner jig 18. When supported by the upper surface 18a of the shape, the inner surface of the corner portion of the work W is in surface contact with the mountain-shaped upper surface 18a of the corner jig 18 even if the work W has been subjected to the hemming process or the work W having the flange portion. As a result, the clamps by the left and right clamps 34 can be satisfactorily and reliably performed.

  In addition, as shown in FIG. 11, the corner jig 18 is a shield gas such as an argon gas formed along the corner of the work W on the top of the corner jig 18 (this shield gas prevents oxidation of the welded portion). A gas supply port 18e formed vertically at the top of the corner jig 18 to communicate the gas groove 18d through which the gas groove 18d flows, the gas passage 17b of the shield gas formed in the jig slide 17 and the gas groove 18d. The shield gas supplied from the gas supply joint 24 to the gas passage 17b of the jig slide 17 flows from the gas supply port 18e into the gas groove 18d.

  Although not shown, the corner jigs 18 have different lengths, and the angle formed between one surface of the upper surface 18a and the other surface is other than 90 degrees. A variety of corner jigs 18 are prepared, such as those that do not have a shape, and can be replaced according to the size and shape of the work W. For example, if a long corner jig 18 is used, a deep box can be manufactured, and the angle formed between one surface of the upper surface 18a of the corner jig 18 and the other surface is 120 degrees. If the corner jig 18 is used, a hexagonal box can be manufactured.

  As shown in FIGS. 6 and 9, the jig slide driving unit 19 includes a rodless cylinder 19 a attached to the lower surface of the mandrel 15 along the mandrel 15, a movable part 19 b of the rodless cylinder 19 a, and a jig slide. And a connecting fitting 19c for connecting the body 17 to the body 17. The working fluid is alternately supplied from two working fluid supply joints 19d provided at both ends of the rodless cylinder 19a to move the corner jig 18 to the retracted position. It is possible to reciprocate in the front-rear direction between (a dashed line position in FIG. 6) and a front position (a solid line position in FIG. 6).

  Although not shown, a normal double-acting cylinder may be used in place of the rodless cylinder 19a, or a ball screw mechanism and a motor may be used for the jig slide body driving unit 19. good.

  The lower jig unit 2 is supported on the front surface of the main body frame 1b via a lower jig unit elevating support mechanism 25 so as to be able to move up and down. 5 and 6, and the lower jig unit 2 as a whole is raised and the corner jig 18 and the clamps 34 on the right and left sides of the clamp unit 3 form a corner of the work W. It can be moved up and down over a clamp position (position shown in FIG. 8) for holding and fixing the portion.

  That is, as shown in FIGS. 4 to 6, the lower jig unit elevating and lowering support mechanism 25 has a vertically oriented jig base 25a fixed to the front surface of the frame 1, and a linear guide 25b on the front surface of the jig base 25a. And a jig vertical slide plate 25c to which the mandrel mounting base 14 of the lower jig unit 2 is fixed, and is fixed to a jig base 25a in a vertical position, and is fixed to the jig vertical slide plate 25c. A hydraulic cylinder 25e connected via a cylinder connecting plate 25d, and the lower jig unit 2 is moved up and down by moving the hydraulic cylinder 25e up and down to move the jig vertical slide plate 25c up and down. Is available.

  The clamp unit 3 is provided on the jig base 25 a of the lower jig unit elevating and lowering support mechanism 25, and presses the corner portion of the work W supported by the corner jig 18 from above to form the mountain shape of the corner jig 18. Left and right clamps 34 and the like that are pressed and fixed to the upper surface 18a of the first and second clamps 34, and one of the right and left clamps 34 (the right clamp 34 in FIG. 5) is moved in the left and right direction (to approach the other clamp 34). , The distance between the left and right clamps 34 can be adjusted finely so that the other clamp 34 (the left clamp 34 in FIG. 5) can be moved and adjusted in the left and right direction. 34 can be finely adjusted, and can be vertically swung. And so as to elastically contact to the upper surface 18a of the Na portion.

  That is, as shown in FIG. 4 to FIG. 8, FIG. 12 and FIG. 13, the clamp unit 3 is a left and right clamp block fixed in a horizontal posture and parallel at a fixed interval at the upper end of the jig base 25a. 26, a front cover 27 for connecting the distal ends of the left and right clamp blocks 26, a right clamp slide base 28 fixed to the lower surface of the right clamp block 26, and a screw in a vertical posture on the lower surface of the left clamp block 26. The left clamp slide base 28 is supported by the clamp guide screw 29 attached thereto so as to be swingable in the vertical direction, and the ball slide guide 30 (consisting of a rail 30a, a block 30b, and a ball 30c) on the lower surface of the left and right clamp slide bases 28. The left and right clamp slide plates 31 are attached to the left and right The right and left clamps 34, which are detachably attached to the slide plate 31 via the clamp holding plate 32 and the clamp lever 33, and press and fix the corner portion of the work W to the upper surface 18a of the corner jig 18, and the left and right clamp slide bases 28. And a left and right clamp slide plate 31, a left and right clamp block adjusting mechanism 35 for moving and adjusting the left and right clamp slide plates 31 in the left and right direction, a left clamp block 26 and a left clamp slide base 28. , The tip of the left clamp 34 is elastically abutted against the upper surface 18 a of the corner portion of the work W supported by the corner jig 18 by urging the left clamp slide base 28 downward. And a plurality of pressure springs 36 (compression coil springs).

  Further, the left and right clamps 34 mainly interrupt the spread of the arc and mainly apply the arc energy to the corners of the work W when welding the corners of the work W, as shown in FIG. As described above, a base-side clamp 34a made of a metal member having an inverted L-shaped cross section and a copper member fixed at the lower end of the base-side clamp 34a and having a distal end formed at an acute angle. And a plate-shaped tip-side clamp 34b. A plurality of clamps 34 having different lengths are prepared for the left and right clamps 34. The clamps 34 are exchanged according to the depth of the box-bent work W, and the corners of the work W are corner-treated regardless of the depth of the work W. The tool 18 can be securely and satisfactorily pressed and fixed to the upper surface 18a of the tool 18.

Further, as shown in FIGS. 8 and 12, the left and right clamp width adjusting mechanisms 35 are inserted into the clamp adjusting table 35a fixed to the lower surface of the clamp slide base 28 and can be freely rotated forward and reverse in a horizontal posture. The clamp adjustment bolt 35b, which is supported and the tip is screwed into the clamp slide plate 31, is interposed between the clamp adjustment base 35a and the clamp slide plate 31 to prevent the clamp adjustment bolt 35b from loosening and to clamp the clamp adjustment bolt 35b. A compression coil spring 35c that urges the slide plate 31 toward the other clamp 34, and a fixing bolt 35d that is screwed into the clamp adjustment base 35a and stops the clamp adjustment bolt 35b from rotating, are provided. When the bolt 35b is rotated forward or backward, the clamp adjustment bolt 35b is rotated once. Clamp slide plate 31 is moved toward the left-right direction by the pitch of the screw formed on the clamp adjustment bolt 35b into.
Accordingly, the left and right clamps 34 attached to the left and right clamp slide plates 31 also move in the left and right direction (the left and right direction in FIG. 12), and the gap between the left and right clamps 34 is adjusted.

  Thus, according to the clamp unit 3, after the distance between the left and right clamps 34 is adjusted by the clamp width adjusting mechanism 35 according to the thickness of the work W to be welded, the work is performed by the left and right clamps 34 and the corner jig 18. When the corner of W is clamped and fixed from above and below, the left clamp 34 can uniformly press the corner of the work W by the action of the pressure spring 36 with reference to the tip of the right clamp 34.

  The torch unit 4 supports a TIG welding torch 53 provided with a constriction nozzle 53c, reciprocates the TIG welding torch 53 along a corner of the work W, and moves in a direction orthogonal to the corner of the work W. It vibrates. The torch unit 4 has a standby position where the welding torch 53 having the constriction nozzle 53c is located above and behind the corner jig 18 at the retracted position, and a welding operation position where the welding torch 53 is located above the corner jig 18. Is reciprocally movable in the front-rear direction across the workpiece W. The welding torch 53 is pulled out from the standby position to the welding operation position when welding the corner portion of the work W supported by the corner jig 18 and the welding torch 53 is moved at a predetermined speed. It moves linearly along the corner of W.

  That is, as shown in FIGS. 14 to 19, the torch unit 4 includes a torch unit base 37 disposed in a horizontal posture in the main body frame 1b, a front and rear rail base 38 fixed to the upper surface of the torch unit base 37, and a front and rear rail. A left and right slide base 40 is supported on the upper surface of the base 38 via a linear guide 39 so as to be able to reciprocate in the front and rear direction, and is disposed between the front and rear rail base 38 and the left and right slide base 40. Motor 41 and a belt transmission mechanism 42 for reciprocating in the left and right directions, a left and right slide base plate 44 supported on the upper surface of the left and right slide base 40 via a linear guide 43 so as to be reciprocally movable in the left and right directions, And the right and left slide base plates 44 are disposed between the right and left slide base plates 44 to reciprocate the left and right slide base plates 44 in the left and right directions. The screw mechanism 45 and the left and right motors 46 that can rotate forward and backward, the vertical slide base 47 provided on the left and right slide base plate 44 and the vertical slide base 47 are supported by the vertical slide base 47 via a linear guide 48 so as to be able to move up and down. A vertical screw plate 49, a ball screw mechanism 50 disposed between the vertical slide base 47 and the vertical slide plate 49 to move the vertical slide plate 49 up and down, and a vertically movable motor 51, which can be rotated forward and backward, and a base end portion. A torch support arm 52 which is fixed to the upper and lower slide plates 49 and has a front end protruding forward from the main body frame 1b in a horizontal position, and a TIG welding torch 53 attached to the front end of the torch support arm 52 and having a constriction nozzle 53c. The left and right slide base 40, the left and right slide base plate 44 and the up and down slide plate 49 can be moved. By welding torch 53 is adapted to move back and forth direction, the lateral direction and the vertical direction.

  In addition, when the ball screw mechanism 45 is rotated in the forward / reverse direction by the left / right motor 46 via the coupling 54 by the left / right motor 46, the left / right slide base 40 reciprocates in the left / right direction orthogonal to the corner portion of the work W, and the left / right slide. The TIG welding torch 53 supported on the base 40 via the vertical slide base 47, the vertical slide plate 49, and the torch support arm 52 also reciprocates in the left-right direction orthogonal to the corner of the work W. That is, in the torch unit 4, the TIG welding torch 53 vibrates in a direction orthogonal to the corner of the work W by operating the ball screw mechanism 45 and the left and right motor 46.

  In this embodiment, the TIG welding torch 53 provided with the constriction nozzle 53c is caused to vibrate within a frequency range of 1 Hz to 10 Hz. Further, as shown in FIG. 23, the amplitude of the TIG welding torch 53 is at least the outer edge (W1d) of the tip surface (W1a) of the metal plate (W1) on one side from a position above the ridgeline (W2d) of the corner portion of the work W. In the upper position.

A stepping motor is used for the left and right motors 46. When a predetermined number of pulse input signals are applied to the left and right motors 46, the output shaft of the left and right motors 46 performs stepping rotation according to the number of input pulses. This rotational movement is transmitted to the ball screw mechanism 45 via the coupling 54, thereby rotating the ball screw shaft of the ball screw mechanism 45 forward or backward by a predetermined angle or a predetermined number of rotations. As a result, the left and right slide bases 40 reciprocate in the left and right directions orthogonal to the corners of the work W.

  In this embodiment, a stepping motor is used for the left and right motors 46. However, any type of motor that can control the rotation angle may be used. For example, a servo motor (DC motor + encoder) Alternatively, an AC servomotor (AC motor + encoder) or an ultrasonic motor may be used.

  As shown in FIG. 20, the TIG welding torch 53 includes a constriction nozzle 53c in which a tungsten electrode rod 53b is inserted inside an outer nozzle 53a, and divides a shielding gas G into an outer side and an inner side of the constriction nozzle 53c. Further, the shield gas G1 inside the constriction nozzle 53c is ejected at a higher speed than the shield gas G2 outside the constriction nozzle 53c. The TIG welding torch 53 having the constriction nozzle 53c as shown in FIG. 20 is known from Japanese Patent Application Laid-Open No. 2012-139704 and WO 2013/157636, and a detailed description thereof will be omitted here.

  Further, the gap between the constriction nozzle 53c of the TIG welding torch 53 and the tungsten electrode rod 53b is considerably narrower than the gap between the outer nozzle 53a and the constriction nozzle 53c, and the inner shield gas ejected from the constriction nozzle 53c. G1 is ejected at a flow rate several times that of the outer shield gas G2 ejected from the gap between the outer nozzle 53a and the constriction nozzle 53c. The TIG welding torch 53 is preferably configured such that the shield gas G1 flowing inside the constriction nozzle 53c is 20 to 60% of the total shield gas G (G1 + G2).

  Incidentally, the TIG welding torch 53 having the constriction nozzle 53c is not affected by the influence of wind and is not affected by the wind as compared with the conventional TIG welding torch 53 not having the constriction nozzle 53c. In addition to the above, there are advantages that a high speed can be achieved and that the bending ductility of the welded portion can be improved.

  The pressing and holding member 5 is disposed at a position higher than the corner jig 18 at the lowered position, and the work supported by the corner jig 18 when the corner jig 18 is raised from the lowered position to the clamp position. The bottom surface of the W near the corner is pressed and held against the tip end surface 18f of the corner jig 18.

  That is, as shown in FIGS. 5, 6, and 8, the pressing and holding member 5 is composed of a plurality of vertically rotatable rollers that can contact the bottom surface of the work W supported by the corner jig 18, and The clamp 34 is provided on a mount 55 fixed to one end of the clamp 34 (in this example, the end of the right clamp 34).

  Specifically, each roller forming the pressing and holding member 5 is formed of a guide roller having a bearing structure, and is supported by shaft fittings 56 fixed to both ends of the mounting base 55 as shown in FIGS. It is supported on a shaft 57 in a horizontal posture in a parallel state and freely rotatable vertically. When the lower jig unit 2 rises from the lowered position to the clamp position, each of these rollers comes into contact with the outer surface of the bottom surface near the corner of the work W supported by the corner jig 18 at the retreat position. The bottom surface of the W is pressed and held against the tip end face 18f of the corner jig 18.

  The pressing and holding member 5 presses and holds the bottom surface of the work W to the corner jig 18 before the corner of the work W is clamped and fixed by the corner jig 18 and the left and right clamps 34 from above and below. It has become. For this reason, the pressing and holding member 5 is disposed at a position lower than the distal ends of the right and left clamps 34 and comes into contact with the bottom surface of the work W before the left and right clamps 34.

  Further, a copper start tab 58 formed in a block shape for generating an initial arc is provided at a position above the pressing and holding member 5 and at an upper end of the mount 55 as shown in FIG.

  Next, using the above-described vibration TIG welding apparatus for corners of the work W, the corners of the metal plate-made work W bent in a box so that no gaps were formed at the four corners were welded together, and one end face was opened. A case where a box-shaped product is manufactured will be described.

  The work W is formed by bending a stainless steel plate having a thickness of 0.6 mm to 1.6 mm into a cylindrical shape. Further, welding conditions such as welding current, arc length, supply amount of shielding gas, running speed of TIG welding torch 53, tip shape of tungsten electrode rod 53b, etc. are optimal according to the material, thickness and width of work W. Of course.

  First, the worker advances the corner jig 18 of the lower jig unit 2 at the lowered position from the retracted position (the dashed-dotted line position in FIG. 6) to the advanced position (the solid line position in FIG. 6). The box-bent work W is set on the jig 18. That is, of the four corner portions of the box-bent work W, the back surface of one corner portion is put on the upper surface 18a of the corner jig 18 and the corner portion of the work W is supported by the corner jig 18 from the back surface side.

  After the work W is set on the corner jig 18, the corner jig 18 at the advance position is retracted to the retracted position, and then the lower jig unit 2 at the lowered position is raised to the clamp position (see FIG. 8), and the corner jig is turned. After the bottom surface near the corner of the work W supported by the jig 18 is pressed and held on the tip end face 18f of the corner jig 18 by the pressing and holding member 5, the corner jig 18 is placed with the corner of the work W facing upward. Is clamped and fixed from above and below by the inclined upper surface 18a and the left and right clamps 34.

  By the way, when the corner portion of the box-bent work W is supported by the corner jig 18 from the back side, the interval between the opposing edges of the two surfaces facing the right angle of the work W is widened by its own weight, and the corner of the work W There may be gaps in the parts.

  Therefore, in this vibration TIG welding apparatus, as shown in FIG. 22, when the corner jig 18 rises from the lowered position to the clamp position, the bottom portion near the corner of the work W is moved by the pressing and holding member 5 to the corner jig 18. Is pressed and held on the front end face 18f of the rim. Therefore, the self-weight of the work W hanging on the two surfaces supported by the corner jigs 18 of the work W is removed, and the corners of the work W return to the original state by the elastic force, and the gap between the corners of the work W is reduced. Disappears.

  When the corner portion of the work W is clamped upward on the corner jig 18, the corner portion of the work W is formed by a pair of left and right metal plates W 1 and W 1 forming the corner portion of the work W, as shown in FIG. Among the W2, the tip surface W1a of one side of the metal plate W1 (for example, the left side metal plate W1) is formed on the inner side surface W2c of the opposite side of the metal plate W2 (for example, right side metal plate W2). The side surface W1b and the front end surface W2a of the metal plate W2 on the opposite side are abutted so as to be flush, or a pair of left and right metal plates W1, which form a corner portion of the work W (not shown). Of the W2, the tip surface W2a of one side of the metal plate W2 (for example, the right side metal plate W2) is formed on the inner side surface W1c of the opposite side of the metal plate W1 (for example, the left side metal plate W1). Opposite side W2b And the distal end face W1a of the metal plate W1 is butted to be flush. When the form of the corner portion of the work W is the former (FIG. 23), the outer edge W2d of the tip end surface W2a of the metal plate W2 on the opposite side (the right metal plate W2) becomes the ridgeline of the corner portion of the work W. I have. Conversely, when the form of the corner portion of the work W is the latter (not shown), the outer edge W1d of the tip end surface W1a of one metal plate W1 (the left metal plate W1) becomes the ridgeline of the corner portion of the work W. I have.

  In this embodiment, the butting form of the corner portion of the work W is the former state, and the outer edge W2d of the tip end surface W2a of the right metal plate W2 is the ridgeline of the corner portion of the work W. .

  When the corner portion of the work W is clamped by the corner jig 18 and the left and right clamps 34 without any gap, the automatic operation switch 8 is turned on.

  Then, the torch unit 4 is operated, and the TIG welding torch 53 is vibrated in a direction orthogonal to the corner portion with the center of the ridge line of the corner portion of the workpiece W (outer edge W2d of the front end surface W2a of the right metal plate W2). At the same time, an arc is generated between the TIG welding torch 53 and the corner of the workpiece W to form a molten pool at the corner of the workpiece W.

  At this time, the amplitude of the TIG welding torch 53 is at least from the position above the ridge line of the corner portion of the workpiece W (outer edge W2d of the front end face W2a of the right metal plate W2) to the outside of the front end face W1a of one metal plate W1. It is to be located above the edge W1d.

  Then, when the arc is stabilized, the TIG welding torch 53 travels along the corner of the work W while vibrating the TIG welding torch 53 in a direction orthogonal to the corner around the ridge line of the corner of the work W. By doing so, the molten pool formed at the corner is moved in the same direction as the TIG welding torch 53, and the corner of the work W is welded together.

  At this time, a molten pool is formed at the corner of the work W while vibrating the TIG welding torch 53 in a direction orthogonal to the corner with the ridgeline of the corner of the work W as a center. Since the TIG welding torch 53 is moved in the same direction as the TIG welding torch 53 to travel to weld the corners of the work W, both sides of the ridge line of the corners of the work W are uniformly melted, and the corners of the work W are melted. The melted metal is rounded due to surface tension, and the corner portion of the work W is formed into a beautiful circular arc shape to have a uniform left and right shape (see FIG. 24).

  When the welding of the corner portion of the work W is completed, the torch unit 4 is retracted from the welding operation position to the standby position, and the lower jig unit 2 is lowered from the clamp position to the lowered position. The tool 18 moves from the retracted position to the advanced position. Thereby, the worker can remove it from the corner jig 18.

  Hereinafter, similarly, the remaining three corners of the work W are sequentially welded by the vibration TIG welding apparatus, and a box-shaped product is manufactured from the box-bent work W.

  As described above, the method and the apparatus for the vibration TIG welding of the corner portion of the workpiece W use the TIG welding torch 53 provided with the constriction nozzle 53c that improves the directivity of the arc, and connect the TIG welding torch 53 to the workpiece W. Because the corner of the work W is welded while vibrating in the direction perpendicular to the corner with the ridgeline of the corner as the center, the corner of the work W has a beautiful arc shape and an even left and right shape Becomes

As a result, when welding the corners of the work W, welding defects such as holes are not generated, and the quality of products manufactured by welding is significantly improved.
In addition, since the corner portion of the work W is formed into a beautiful arc shape by the corner welding, finishing work such as sander finish or buff finish is not required after welding the corner portion of the work W, which requires much labor and time. And the problem of noise can be eliminated.
Furthermore, since the TIG welding torch 53 is vibrated, the temperature of the molten pool is made uniform, and the metal structure can be prevented from becoming coarse.

  FIG. 25 is a photograph showing the appearance of a box-shaped workpiece made of a thin steel plate when the corners are welded by the method of the present invention and the conventional method, the target position of the tungsten electrode rod by the method of the present invention and the conventional method, and the front side. Are photographs showing the appearance of the bead and the appearance of the bead on the back side, respectively.

  That is, according to the method of the present invention, the tip of the tungsten electrode rod 53b of the TIG welding torch 53 is set at the center position of the corner portion of the work W (the position above the ridge line of the corner portion). Welding was performed with a vibration of 0.3 mm (amplitude: 0.15 mm).

  On the other hand, in the conventional method, the tip of the tungsten electrode rod 53b of the TIG welding torch 53 is set to the right position (or the left position) from the center position of the corner of the work W, and the TIG welding torch 53 vibrates. Without welding.

The welding conditions were a thin steel plate made of SUS304 having a thickness of 0.6 mm, a tungsten electrode rod 53b containing thorium, a tip angle of the tungsten electrode rod 53b: 25 °, a width of the right and left clamps 34: 2.0 mm, a corner treatment. Width of gas groove 18d of the tool 18: 2.0 mm, torch gas: 8.0 liter / min, back gas: 1.0 liter / min, arc length: 1.00 mm, AVC set voltage: 11.20 V (AVC set voltage) Is the set voltage for arc voltage control.), And the vibration width of the torch 53 for TIG welding (only in the present invention): 0.3 mm.

  As is clear from the photograph of FIG. 25, in the method of the present invention in which a vibration of 0.3 mm was applied to the left and right, the bead formed at the corner portion of the work W had a uniform left and right R shape. The welding back bead is located in the middle of the back side of the corner portion of the work W.

  On the other hand, in the conventional method, a welding bead is formed at a target position of the tungsten electrode rod 53b, and a corner remains on the opposite side of the target position. For this reason, finishing such as sanding and buffing after the welding is completed is required. Also, the weld back bead is clearly shifted toward the target position. Furthermore, the position of the TIG welding torch 53 must be reset according to the shape of the corners of the workpiece W, and if the operator sets it incorrectly, poor welding (perforation or poor fusion) may occur. Will be.

  As described above, the vibration TIG welding method and the vibration TIG welding apparatus of the present invention have advantages such as excellent welding appearance at the corner portion of the work W, reduction in welding defects, and reduction in the number of finishing steps. Have.

  The width (size) of the arc formed at the corner of the work W in the left-right direction can be adjusted by the magnitude of the current and the vibration of the TIG welding torch 53. When the current is increased, the width in the left-right direction of the arc formed at the corner of the workpiece W is increased, and the radius is increased. The width is reduced and the radius is reduced. To the extent that the magnitude of the arc formed at the corner of the workpiece W cannot be adjusted due to the strength of the current, it is adjusted by the vibration width of the TIG welding torch 53.

  In the above-described embodiment, the corners of the box-bent workpiece W are welded together using the vibration TIG welding device. However, in other embodiments, two thin metal plates are formed by the vibration TIG welding device. The corner portion of the work W formed by abutting at right angles may be welded, or the corner portion of the work W formed by bending a thin metal plate into a rectangular tube shape by an automatic corner welding device. You may do it.

  Further, in the above embodiment, the amplitude of the TIG welding torch 53 is set from the position above the ridge line of the corner portion of the work W to the position above the outer edge of the tip end surface of one metal plate. In the embodiment, the amplitude of the TIG welding torch 53 may be set to a position slightly outside from a position above the ridgeline of the corner portion of the work W to a position above the outer edge of the tip end surface of one metal plate.

  4 is a torch unit, 18 is a corner jig, 34 is a right and left clamp, 53 is a TIG welding torch, 53a is an outer nozzle, 53c is a constriction nozzle, W is a work, W1 and W2 are metal plates forming a work, and W1a. , W2a are the end surfaces of the metal plate, W1b, W2b are the outer surfaces of the metal plate, W1c, W2c are the inner surfaces of the metal plate, and W1d, W2d are the outer edges of the end surface of the metal plate.

Claims (2)

  After clamping the corner of the work (W) formed by butting the ends of the metal plates (W1) and (W2) at right angles to each other with the ridge line facing upward, the shield gas (G) is set to the outside. A TIG welding torch (53) having a constriction nozzle (53c) inside an outer nozzle (53a) so as to flow inward and eject the inner shield gas (G1) at a higher speed than the outer shield gas (G2). The work (W) is vibrated in a direction orthogonal to the ridge line of the corner of the work (W), and is run along the corner of the work (W) to weld the corner of the work (W). A TIG welding method, wherein a tip surface (W1a) of a metal plate (W1) on one side of a pair of left and right metal plates (W1) and (W2) forming a corner portion of the work (W) is formed on the opposite side. Metal plate (W2) A work (W) formed by abutting the inner surface (W2c) such that the outer surface (W1b) of one metal plate (W1) and the tip surface (W2a) of the opposite metal plate (W2) are flush. ) Is clamped in such a position that the ridge line faces upward, and the TIG welding torch (53) is turned on at least one side of the metal plate (W1) from the position above the ridge line of the corner portion of the work (W). The TIG welding torch (53) and the work (W) are vibrated in a direction perpendicular to the ridge line of the corner of the work (W) so as to reach a position above the outer edge (W1d) of the front end surface (W1a) of the work (W). A) a molten pool is formed at the corner of the workpiece (W) by the arc generated between the workpiece and the corner of the workpiece (W), and the TIG welding torch (53) is caused to travel along the corner of the workpiece (W). The melting step Vibration TIG welding method of the corner portion of the workpiece, characterized in that so as to weld the corner portion of the workpiece (W) while Le is moved in the same direction as the torch TIG welding (53).   The vibration of the corner portion of the work according to claim 1, wherein the torch (53) for TIG welding provided with the constriction nozzle (53c) is caused to vibrate within a frequency range of 1 Hz to 10 Hz. TIG welding method.